Overhaul of Class 57, EMD 645 Diesel powered locomotive.Client:
Railway Vehicle Engineering LtdIndustry:
Replacement and re-alignment of Brush alternator, Replacement of turbocharger, clutch drive and spring drive assembly, Overhaul of original CA coolers and modification of Lub oil cooler, Replacement of all gear driven water and oil pumps, Crankshaft inspeDate:
April 2014 – March 2015
GSE was awarded a contract to carry out major engine overhauls of 2 Stroke, 12 cylinder 645 series fitted to First Great Westerns fleet of Class 57 Locomotives. Work was carried out on site at RVEL’s Derby workshops, whilst the locomotive underwent extensive modification work.
Work specification incorporated within the contract included:
- Replacement and re-alignment of Brush alternator.
- Replacement of turbocharger, clutch drive and spring drive assembly.
- Overhaul of original CA coolers and modification of Lub oil cooler.
- Replacement of all gear driven water and oil pumps
- Crankshaft inspection and main bearing replacement.
- LE bearing replacement.
- Original Cylinder head overhaul.
- Overhaul original Pistons, replace piston rings and thrust washers
- Complete Full load bank testing of power unit on completion of overhaul.
Work commenced with removal of the Brush alternator, sent for overhaul at Erik’s (UK), whilst a team of 4 GSE engineers progressed the service work of the EMD main engine. Cylinder heads were removed for overhaul at GS workshops, whilst pistons were removed in sequence, to allow replacement of piston rings and thrust washers, allowing connecting rods and piston carriers to be left in-situ.
Main bearings and LE bearings were replaced throughout each engine and tensioned as per OEM specification.
Camshafts assemblies were inspected and replaced as required, along with replacement of rocker arms, valve lash adjusters and unit fuel injectors with UTEX exchange parts. Woodward PGA governors were replaced, with individual fuel rack and injector timing reset on all cylinders.
All gear driven Water and Oil pumps were replaced, along with engine shutdown protection blocks.
Prior to completion of each engine overhaul and subsequent load bank testing, each sump and air box chamber were thoroughly cleaned and examined.
On completion of each engine overhaul, re-conditioned alternators were fitted and re-aligned to the main engines. To facilitate the subsequent alignment of a replacement alternator, the original bedplates were re-bushed, prior to fitment of exchange alternator and re-drilled and bushed on completion of re-alignment.
Reconditioned Turbochargers and clutch assemblies were refitted to the main engine, along with ultrasonically cleaned CA coolers.
Finally a full load bank power test was conducted on completion of each locomotive overhaul. Individual power unit performance was monitored, adjusted as required and recorded throughout the test.